Efficacy of Sodium Hyaluronate and Carboxymethylcellulose in Treating Mild to Moderate Dry Eye Disease

Evaluation of a Novel Artificial Tear in the Prevention and Treatment of Dry Eye in an Animal Model

Purpose: To evaluate effects of a novel multi-ingredient artificial tear formulation containing carboxymethylcellulose (CMC) and hyaluronic acid (HA) in a murine dry eye model.

Methods: Dry eye was induced in mice (C57BL/6) using an intelligently controlled environmental system (ICES). CMC+HA (Optive Fusion™), CMC-only (Refresh Tears^®), and HA-only (Hycosan^®) artificial tears and control phosphate-buffered saline (PBS) were administered 4 times daily and compared with no treatment (n = 64 eyes per group). During regimen 1 (prevention regimen), mice were administered artificial tears or PBS for 14 days (starting day 0) while they were exposed to ICES, and assessed on days 0 and 14. During regimen 2 (treatment regimen), mice exposed to ICES for 14 days with no intervention were administered artificial tears or PBS for 14 days (starting day 14) while continuing exposure to ICES, and assessed on days 0, 14, and 28. Corneal fluorescein staining and conjunctival goblet cell density were measured.

Results: Artificial tear-treated mice had significantly better outcomes than control groups on corneal staining and goblet cell density (P < 0.01). Mice administered CMC+HA also showed significantly lower corneal fluorescein staining and higher goblet cell density, compared with CMC (P < 0.01) and HA (P < 0.05) in both regimens 1 and 2.

Conclusions: The artificial tear formulation containing CMC and HA was effective in preventing and treating environmentally induced dry eye. Improvements observed for corneal fluorescein staining and conjunctival goblet cell retention suggest that this combination may be a viable treatment option for dry eye disease.

Comparison of cytotoxicity and wound healing effect of carboxymethylcellulose and hyaluronic acid on human corneal epithelial cells

AIM

To investigate the cytotoxic effect on human corneal epithelial cells (HCECs) and the ability to faciliate corneal epithelial wound healing of carboxymethylcellulose (CMC) and hyaluronic acid (HA).

METHODS

HCECs were exposed to 0.5% CMC (Refresh plus(®), Allergan, Irvine, California, USA) and 0.1% and 0.3% HA (Kynex(®), Alcon, Seoul, Korea, and Hyalein mini(®), Santen, Osaka, Japan) for the period of 30min, and 4, 12, and 24h. Methyl thiazolyl tetrazolium (MTT)-based calorimetric assay was performed to assess the metabolic activity of cellular proliferation and lactate dehydrogenase (LDH) leakage assay to assess the cytotoxicity. Apoptotic response was evaluated with flow cytometric analysis and fluorescence staining with Annexin V and propiodium iodide. Cellular morphology was evaluated by inverted phase-contrast light microscopy and electron microscopy. The wound widths were measured 24h after confluent HCECs were scratch wounded.

RESULTS

The inhibitory effect of human corneal epithelial proliferation and cytotoxicity showed the time-dependent response but no significant effect. Apoptosis developed in flow cytometry and apoptotic cells were demonstrated in fluorescent micrograph. The damaged HCECs were detached from the bottom of the dish and showed the well-developed vacuole formations. Both CMC and HA stimulated reepithehlialization of HCECs scratched, which were more observed in CMC.

CONCLUSION

CMC and HA, used in artificial tear formulation, could be utilized without any significant toxic effect on HCECs. Both significantly stimulated HCEC reepithelialization of corneal wounds.

Comparison of novel lipid-based eye drops with aqueous eye drops for dry eye: a multicenter, randomized controlled trial

Background

Dry eye may be caused or exacerbated by deficient lipid secretion. Recently, lipid-containing artificial tears have been developed to alleviate this deficiency. Our study compared the efficacy, safety, and acceptability of lipid-containing eye drops with that of aqueous eye drops.

Methods

A non-inferiority, randomized, parallel-group, investigator-masked multicenter trial was conducted. Subjects with signs and symptoms of dry eye were randomized to use one of two lipid-containing artificial tears, or one of two aqueous artificial tears. Subjects instilled assigned drops in each eye at least twice daily for 30 days. The primary efficacy analysis tested non-inferiority of a preservative-free lipid tear formulation (LT UD) to a preservative-free aqueous tear formulation (AqT UD) for change in Ocular Surface Disease Index (OSDI) score from baseline at day 30. Secondary measures included OSDI at day 7, tear break-up time (TBUT), corneal and conjunctival staining, Schirmer’s test, acceptability and usage questionnaires, and safety assessments.

Results

A total of 315 subjects were randomized and included in the analyses. Subjects reported instilling a median of three doses of study eye drops per day in all groups. At days 7 and 30, all groups showed statistically significant improvements from baseline in OSDI (P<0.001) and TBUT (P≤0.005). LT UD was non-inferior to AqT UD for mean change from baseline in OSDI score at day 30. No consistent or clinically relevant differences for the other efficacy variables were observed. Acceptability was generally similar across the groups and there was a low incidence of adverse events.

Conclusion

In this heterogeneous population of dry eye subjects, there were no clinically significant differences in safety, effectiveness, and acceptability between lipid-containing artificial tears and aqueous eye drops. The results suggest that lipid-containing artificial tears can be used to counteract lipid deficiency that is common in dry eye, without compromising overall acceptability.

Efficacy and safety of two new formulations of artificial tears in subjects with dry eye disease: a 3-month, multicenter, active-controlled, randomized trial

Purpose

To evaluate and compare the efficacy and safety of two investigational artificial tear formulations (CHO-1 and CHO-2) containing carmellose sodium, hyaluronic acid at different concentrations, and osmoprotectants, with a standard carmellose sodium-containing formulation (Refresh Tears [RT]) in the treatment of dry eye disease.

Subjects and methods

In this 3-month, double-masked, multicenter study, subjects (n=305) were randomized 1:1:1 to receive CHO-1, CHO-2, or RT, used as needed but at least twice daily. The primary endpoint was change in ocular surface disease index (OSDI) score from baseline to day 90. Other key outcomes included symptoms evaluated on a visual analog scale, corneal and conjunctival staining, and adverse events.

Results

OSDI scores and dry eye symptoms showed a rapid and sustained reduction from baseline in each group. Both CHO-1 and CHO-2 met the primary efficacy endpoint of noninferiority to RT in day 90 OSDI score change from baseline. OSDI ocular symptoms subscale improved more with CHO-1 than CHO-2 (P=0.048). In subjects with clinically relevant baseline ocular surface staining (>14 total score of a maximum of 55), day 90 improvements were greater with CHO-1 and CHO-2 than RT (P≤0.044). Day 90 improvements in OSDI ocular symptoms subscale scores were also greater with CHO-1 than RT (P<0.007) in subjects with clinically relevant ocular staining. All treatments were well tolerated.

Conclusion

Both combination artificial tear formulations were efficacious and well tolerated in subjects with dry eye. CHO-1 demonstrated the best performance in improving ocular symptoms and reducing ocular staining in this heterogeneous study population.

A randomized crossover study comparing trehalose/hyaluronate eyedrops and standard treatment: patient satisfaction in the treatment of dry eye syndrome

Dry eye is a common disorder in routine ophthalmological practice, and a better understanding of the complex pathophysiology is leading to improved treatment. Thealoz Duo(®) is a novel artificial tear preparation containing two active ingredients: Trehalose, a naturally occurring disaccharide with anhydrobiotic functions in many organisms, and hyaluronate, a widely distributed anionic glycosaminoglycan polysaccharide with lubricative and water-retaining properties in biological systems. In a randomized, single center, open label, crossover study, 17 adult patients with moderate-to-severe dry eye syndrome were randomized to treatment with Thealoz Duo(®) (combining trehalose and hyaluronic acid) or Systane(®). Patients received 7 days of treatment. The primary efficacy variable was patient satisfaction evaluated by a 0-100 visual analog scale evaluated on days 0 and 7 of treatment. Secondary parameters included ocular surface disease index (OSDI), symptoms of dry eye, ocular staining scores (fluorescein and lissamine green), ocular clinical signs, Schirmer test, tear breakup time, and global efficacy assessed by the patient and the investigator. Seventeen patients were included. Patient satisfaction improved from 44.5±19.0 to 70.2±19.2 mm during Thealoz Duo(®) treatment and from 47.2±23 to 57.1±19.1 mm during Systane(®) treatment (P=0.043, mixed-effects analysis of covariance). Two secondary efficacy parameters (dry eye symptoms and the impact of their symptoms on work) showed statistically significant advantages for Thealoz Duo(®) over Systane(®). There were no statistically significant advantages for Systane(®) over Thealoz Duo(®) for any measured parameter. No adverse events were reported. Thealoz Duo(®) appears to be an effective combination of two active ingredients for the treatment of dry eye and is at least as effective as Systane(®).

Efficacy of 1% carboxymethylcellulose sodium for treating dry eye after phacoemulsification: results from a multicenter, open-label, randomized, controlled study

BACKGROUND

For patients who experience dry eye after phacoemulsification, vision and quality of life can significantly deteriorate. In this study, the efficacy and safety of carboxymethylcellulose sodium (CMC) 1% ophthalmic solution combined with conventional therapy in treating dry eye signs and symptoms after phacoemulsification were evaluated.

METHODS

In this prospective, multicenter, open-label, controlled study, 180 patients with age-related cataract were randomized to treatment with conventional therapy plus CMC 1% (n = 90) or to conventional therapy only (control group, n = 90) after phacoemulsification and intraocular lens implantation. Tear breakup time (TBUT), the Schirmer test with anesthesia, and fluorescein and lissamine green staining were performed. The Ocular Surface Disease Index (OSDI) questionnaire and a patient subjective symptom evaluation were administered preoperatively (baseline) and postoperatively at 7 and 30 days.

RESULTS

TBUT was significantly longer in the treatment group compared with the control group at day 7 (8.5 ± 5.5 versus 6.6 ± 3.8 s; P = 0.0475) and day 30 (9.0 ± 5.9 versus 6.7 ± 4.8 s; P = 0.0258) after surgery. Compared with baseline, TBUT significantly increased in patients in the treatment group (P < 0.001 at both day 7 and day 30) with a presurgical diagnosis of dry eye, but significantly decreased in patients in the control group (P < 0.02 at both day 7 and day 30) with no prior diagnosis of dry eye. Fluorescein and lissamine staining, OSDI questionnaire and subjective symptom scores all improved from baseline, with no significant differences between the two groups. No significant differences in tolerability and safety were observed between the group receiving CMC and conventional therapy, and those receiving conventional therapy only.

CONCLUSION

Treatment with CMC 1% can provide significant improvement in tear film stability after phacoemulsification for age-related cataract.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02028754 (Date of registration: Jan. 6, 2014).

Efficacy of hypotonic 0.18% sodium hyaluronate eye drops in patients with dry eye disease

PURPOSE

The aim of this study was to evaluate the efficacy of hypotonic 0.18% sodium hyaluronate (SH) eye drops under the clinical settings of the dry eye workshop treatment guideline for mild dry eye disease (DED).

METHODS

This analysis included 60 patients with DED. Patients with level 1 DED were treated with either isotonic 0.1% SH (group 1) or with hypotonic 0.18% SH eye drops (group 2). Patients with level 2 DED were treated with 0.1% fluorometholone, 0.05% cyclosporine A, and either isotonic 0.1% SH (group 3) or hypotonic 0.18% SH (group 4) eye drops. Tear film breakup time (TBUT), Schirmer test, corneal staining with fluorescein, and ocular surface disease index score were recorded at baseline, 1 month, and 3 months after treatment.

RESULTS

In group 2, TBUT at 3 months (P = 0.03) and corneal staining scores at 1 and 3 months (P ≤ 0.03) were significantly improved after the treatment compared with baseline scores, whereas these parameters were not changed during the follow-up period in group 1. In groups 3 and 4, TBUT and corneal staining scores at 1 and 3 months, and ocular surface disease index score and Schirmer test results at 3 months after the treatment showed significant improvements compared with the baseline score (P < 0.05). Group 4 patients showed an extended TBUT and an improved corneal staining score (P ≤ 0.01) at 3 months after treatment, compared with the values of group 3.

CONCLUSIONS

Hypotonic 0.18% SH eye drops seemed to be effective in improving tear film stability and ocular surface integrity compared with isotonic 0.1% SH eye drops in patients with mild DED.

Age-related changes of the ocular surface: a hospital setting-based retrospective study

Purpose. To investigate the effects of age on the prevalence of ocular surface diseases (OSD), adherence to treatment, and recovery rates. Patients and Methods. Retrospective analysis of 3000 clinical records from a first-level general ophthalmology clinic. Patients with OSD were prospectively submitted a questionnaire to assess compliance and recovery rates. Results. OSD prevalence was 10.3%. Patients with OSD were significantly older than patients without it: 67.5 ± 20.3 versus 57.0 ± 22.0 years (P = 0.036). No significant difference in season distribution was shown. Dry eye disease (DED) represented 58% of OSD; its prevalence increased with age until 80 years old and suddenly decreased thereafter. Asymptomatic DED was 37%. Adherence to treatment in OSD was very high (94%); recovery rates were lower in patients aged 21-40 and 61-80 (resp., 65.5% and 77.8%) and this was associated with higher OSDI scores. Tear substitutes represented 50% of all prescribed medications; their use increased with age. Discussion. In a "real-life" low-tech setting, OSD showed a prevalence of 10.3%. DED was the most prevalent disease, and it was asymptomatic in more than 1/3 of cases.

The role and treatment of inflammation in dry eye disease

Dry eye syndrome is a common ocular surface problem, affects 10-30 % of the population, especially in those who are older than 40 years. As a consequence of the demographic pressure created by the aging population, its prevalence is expected to increase as well as its burden on ophthalmologic practices. Thus, understanding the complex underlying mechanisms and development of thoughtful, effective strategies that involve these mechanisms are critical. Many factors causing ocular surface damage and inflammation have been shown to contribute to the etiopathogenesis. Increased osmolarity induces ocular surface inflammation leading to disruption of both the quality and quantity of tears. Pathologic tear function and the ocular surface inflammation affects the neural arcade and increases apoptosis in the ocular surface cells thus creating a viscous cycle for dry eye by causing unstable and hyperosmolar tears. Thus, the treatment objective is to prevent severe dry eye complications via preventing inflammation and apoptosis of the ocular surface cells. The ultimate target is a normalized ocular surface, increased tear stability, and decreased osmolarity of the tear film. In the light of current literature, this review aims to elucidate the role of inflammation as the main etiological factor in dry eye disease and discuss current therapeutic approaches to overcome it.

An update on dry eye disease molecular treatment: advances in drug pipelines

INTRODUCTION

Dry eye disease is a common disorder provoking changes in tear film and ocular surface. Untreated dry eye could cause ocular infections, corneal ulcer and blindness. Only a few drugs are authorized so far for the treatment of dry eye disease and the possibilities of evolution in this sector are immense. Consequently, a significant number of new potential solutions are under development or placed in the pharmaceutical pipeline, promising better results and lesser side effects.

AREAS COVERED

In this article, the corresponding literature and recent Phase III clinical trial data and the corresponding literature, for dry eye disease treatment are reviewed, revealing the new strategic movements in drug pipelines.

EXPERT OPINION

From the clinical trial results, the advancement in tear substitutes and secretagogues in addressing specific deficiencies of tear components even though not resolving the underlying conditions of the disease is evident. The vast majority of new compounds under development are anti-inflammatories, steroids, non-steroids and antibiotics; however, there are also some novel lubricating drops and mucin-tear secretagogues. A future aggressive therapy for dry eye, depending on the severity of the symptoms, would include combinations of soft steroids, anti-inflammatories, such as cyclosporine A, with the addition of the new polyvalent mucin and tear secretagogues.

In vitro efficacy of ocular surface lubricants against dehydration

PURPOSE

To compare 3 ocular lubricants containing sodium hyaluronate (SH), carboxymethylcellulose (CMC), and hydroxypropyl methylcellulose (HPMC) for their ability to enhance water retention and to protect human corneal epithelial cells (HCECs) from dehydration.

METHODS

Experiments were performed using 0.1% and 0.3% solutions of the 3 lubricants diluted in Milli-Q water for the water retention assays and in DMEM/F12 culture medium for the cell viability assays. Five milliliters of each of the lubricants was dropped onto a filter paper, and the paper was kept in an open container at 25°C and a humidity of 36% to 38%. The weight of the paper was measured hourly for 4 hours. In the second set of experiment, cultured HCECs were exposed to the test lubricants for 60 minutes, and the lubricants were removed. Cells were then exposed to room air for up to 60 minutes. Cells were then incubated with a vital dye, and the absorption of the reduced form of the dye was measured. The cell survival rate was compared for the 3 lubricants.

RESULTS

Filter papers moistened with both 0.1% and 0.3% SH were significantly heavier than those moistened with CMC and HPMC at all time points. The survival rate of HCECs was significantly higher at most times with 0.1% and 0.3% SH than with CMC and HPMC solutions. The effects of CMC were not significantly different from those of HPMC.

CONCLUSIONS

These findings indicate that SH is significantly better for water retention and protection of HCECs from dehydration than HPMC and CMC.

New agents for treating dry eye syndrome

Dry eye syndrome (DES) is characterized by an inadequate volume and/or quality of tears resulting in chronic ocular surface irritation and inflammation. Affecting up to 30 % of adults, DES has a considerable impact on visual function and quality of life. DES may complicate allergic ocular disease and allergy medication may exacerbate DES. The pathophysiology of DES involves osmotic, mechanical and inflammatory insults to the tear film, epithelium and subepithelial nerve plexus. Various immune-related molecular targets have been the focus of research aimed at developing new therapeutic agents for treating DES. This article provides an overview of established, new and future agents for treating DES.

Dry eye disease treatment: a systematic review of published trials and a critical appraisal of therapeutic strategies

Dry eye disease (DED) treatment is an area of increasing complexity, with the emergence of several new treatment agents in recent years. Evaluation of the efficacy of these agents is limited by heterogeneity in outcomes definition and the small number of comparative studies. We provide a systematic review of clinical trials (CTs) related to DED treatment and a critical appraisal of CT public databases. CT reports obtained from eight databases were reviewed, as well as public free-access electronic databases for CT registration. Data evaluation was based on endpoints such as symptoms, Schirmer test, ocular surface staining scores, recruitment of patients, type and efficacy of the drug, and the design and site of performance of the study. Forty-nine CTs were evaluated involving 5,189 patients receiving DED treatment. Heterogeneity in study design prevented meta-analysis from yielding meaningful results, and a descriptive analysis of these studies was conducted. The most frequent categories of drugs for DED in these studies were artificial tears, followed by anti-inflammatory drugs and secretagogues. Although 116 studies have been completed, according to the registration database for clinical trials, only 17 of them (15.5%) were published. Out of 185 registered CTs related to DED, 72% were performed in the USA. The pharmaceutical industry sponsored 78% of them. The identification of effective DED treatment strategies is hindered by the lack of an accepted set of definitive criteria for evaluating disease severity.

The Ex Vivo Eye Irritation Test (EVEIT) in evaluation of artificial tears: Purite-preserved versus unpreserved eye drops

OBJECTIVE

Preservatives in artificial tears cause controversy. New developments such as the Purite system have been introduced into the market, with the promise of little damage to the corneal surface. We wanted to give insight into the differences in the effect of preserved and unpreserved artifical tears on rabbit corneas cultured with the Ex Vivo Eye Irritation Test (EVEIT) system.

MATERIALS

We compared the two artifical tears products Hylo Comod and Optive being dropped for 72 hours each hour one drop onto the corneal surface.

METHODS

Each cornea was mechanically wounded with four epithelial defects on each cornea with a size of 3 to 4.5 mm(2). With n = 4 corneas in the Hylo-Comod and n = 4 corneas in the Optive group, we exposed the corneal surfaces to repeated doses of these artificial tears for 3 days. We observed healing of corneal erosions and surface epithelial integrity with sodium-fluoresceine staining under cobalt blue light illumination.

RESULTS

We found nearly complete healing of epithelial defects with both artificial tears. The Hylo-Comod group healed significantly faster. After 72 hours, the vast majority of epithelial defects were closed. All corneas exposed to Purite showed superficial stippling, whereas the HyloComod group did not show any stippling of the cornea; this difference was significant.

DISCUSSION

Epithelial healing and recovery in the EVEIT system is observed in both groups, confirming the concept of artificial tears as a supporting factor of corneal health and healing. The superficial stippling of the corneal epithelium was observed only in the Optive group. This effect is considered as a marker of dry eye syndrome, and should be prevented by the application of artificial tears. Preservative-free eye drops such as HyloComod improve healing, and prevent symptoms of dry eye syndrome in the EVEITsystem. Compared to EVEIT results of former experiments with benzalconium chloride-preserved eye drops, Optive promoted healing of corneal erosions.